Adhesive tapes have been in wide use in the past as closures for interconnecting container parts. For the purposes of this application, the term "container part" includes all containers such as boxes, cartons or the like and any portion thereof, such as joints, lids, closure flaps, and the interconnecting of one container to another container. Such containers are typically constructed from a rigid, lightweight material having high strength, such as corrugated fiberboard, paperboard or the like.
It is frequently desirable to open, disconnect or dismantle a container part. For instance, a container may be opened, emptied and then "knocked down" for storage and subsequent reassembly and reuse. With conventional adhesive tape closures, it is necessary to use a knife or the like to sever the tape closure and disconnect the container parts. This is costly, time consuming, and may damage the contents of the container. Alternatively, the adhesive tape closure may be torn or pulled from the container parts, tending to damage or destroy the container and render it unsuitable for reuse.
U.S. Pat. No. 4,041,202, issued to Williams and entitled "Strippable Tape" represents one attempt to overcome these limitations. In the Williams patent, an upper tape layer is provided having a relatively high internal bond strength that is releasably adhered to a lower tape layer having a relatively low internal bond strength. A medial slit divides the lower tape layer into two adjacent abutting segments. The laminated tape is applied to container parts to adhesively interconnect them. To disconnect the container parts, the upper tape layer is delaminated and the lower tape layer separated at the medial slit.
However, the Williams patent still exhibits several undesirable limitations. It is laborious to engage and peel away a corner or edge of the upper tape layer to delaminate it from the lower tape layer. This results in unnecessary delay and difficulty in disconnecting the container parts.
Further, as the upper tape layer is delaminated from the lower tape layer, the lower tape layer has a tendency to adhere to the upper tape layer and delaminate from the container part, particularly along the medial slit, with the undesirable affects previously discussed.